Beamforming Method and Beamforming Apparatus

ABSTRACT

A beamforming method includes: initializing data of array elements of an antenna array and calculating a current beam pattern based on the initialized data; calculating a difference value between the current beam pattern and a goal beam pattern, and determining data which makes the difference value minimum respectively for each array element using a numerical method in turn from the first array element to the last array element, with the data of other array elements being held and determined data replacing previous data; and generating a beamforming vector using the determined data and generating signals to be transmitted using the beamforming vector. A beamforming apparatus is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International PatentApplication No. PCT/CN2015/073798 filed on Mar. 6, 2015, the contents ofwhich are incorporated by reference herein in their entirety.

FIELD OF THE TECHNOLOGY

Aspects of the present invention relate to an antenna array system, andmore particularly to a beamforming method and a beamforming apparatus.

BACKGROUND OF THE INVENTION

Antennas which are used to transmit and receive radio waves have beenwidely applied in systems such as telecommunications, Wireless LocalArea Networks (WLANs), television broadcasting and radars, etc. Since asingle antenna has many limits, for example it provides a low value ofdirectivity, antenna arrays which each consists of more than one singleantenna, i.e. antenna element, have been developed.

In an antenna array, by combining antenna elements in such a way thatsignals at particular angles experience constructive interference whileothers experience destructive interference, beamforming technique canachieve good spatial selectivity, and thus has been rapidly developed inrent decades.

In order to implement beamforming, many methods, such as ConvexOptimization, Orthogonal Method and metaheuristic methods, have beenproposed. Among these beamforming methods, Convex Optimization canrealize an optimism object of maximizing sidelobe attenuation andminimizing mainlobe ripple, but cannot be applied to realize an optimismobject of matching a given beam pattern. In contrast, Orthogonal Methodcan be used to realize the beam pattern matching problem in some cases,for example in case that the object beam pattern can be perfectlyreached. But if the object beam pattern cannot be exactly reached, forexample, it is just an object which can be approached rather than beingreached, or if the optimism object is to maximizing sidelobe attenuationand minimizing mainlobe ripple, Orthogonal Method is unable to provide asatisfactory result. That is, none of Convex Optimization and OrthogonalMethod has a wide range of use.

As another kind of beamforming methods, metaheuristic methods includeGenetic Algorithms (GA), Differential Evolution Algorithm (DEA), andParticle Swarm Optimization (PSO) and so on. Although metaheuristicmethods can realize both of the above-mentioned optimism objects andthus have a wide range of use, they have a very low computing speed,which makes them not practical in the field of antenna arrays.

Accordingly, there is a need to develop a beamforming method and abeamforming apparatus which not only have a wide range of use but alsohave a fast computing speed.

SUMMARY OF THE INVENTION

Aspects of the present invention are directed toward a beamformingmethod which has both of a wide range of use and a fast computing speed.

Additional aspects of the present invention are directed toward abeamforming apparatus which has both of a wide range of use and a fastcomputing speed.

According to aspects of the present invention, a beamforming methodincludes:

initializing data of array elements of an antenna array and calculatinga current beam pattern based on the initialized data;

calculating a difference value between the current beam pattern and agoal beam pattern, and determining data which makes the difference valueminimum respectively for each array element using a numerical method inturn from the first array element to the last array element, with thedata of other array elements being held and determined data replacingprevious data; and

generating a beamforming vector using the determined data and generatingsignals to be transmitted using the beamforming vector.

In one embodiment, the beamforming method further comprises repeatingthe step of determining data until a difference between the currentdifference value and the previous difference value is less than a presetthreshold.

In another embodiment, the beamforming method further comprisesestablishing a goal beam pattern based on an optimism object if theoptimism object does not include the goal beam pattern.

According to additional aspects of the present invention, a beamformingapparatus includes:

an input receiving unit configured to receive a goal beam pattern;

a data initializing unit configured to initialize data of array elementsof an antenna array pattern and calculate a current beam pattern basedon the initialized data;

a data calculation unit configured to calculate a difference valuebetween the current beam pattern output from the data initializing unitand the goal beam pattern output from the input receiving unit, anddetermine data which makes the difference value minimum respectively foreach array element using a numerical method in turn from the first arrayelement to the last array element, with the data of other array elementsbeing held and determined data replacing previous data;

a beamforming vector generating unit configured to generate abeamforming vector using the determined data sent from the datacalculation unit; and

a signal generating unit configured to generate signals to betransmitted using the beamforming vector sent from the beamformingvector generating unit.

In one embodiment, the beamforming apparatus further comprises athreshold presetting unit configured to preset a threshold, and the datacalculation unit is further configured to repeat the step of determiningdata until a difference between the current difference value and theprevious difference value is less than the preset threshold output fromthe threshold presetting unit.

In another embodiment, the input receiving unit is further configured toestablish a goal beam pattern based on an optimism object if theoptimism object does not include the goal beam pattern.

With the beamforming method and the beamforming apparatus describedabove, since a goal beam pattern is determined at first, it can realizethe optimism object of beam pattern matching if the goal beam patterncan be reached. Even if the goal beam pattern cannot be reached and canonly be approached, since iteration methods are used in an embodiment,rather than direct computation like in Orthogonal Method, a good resultcan also be provided. Thus compared with Orthogonal Method, it has awide range of use.

Further, in another embodiment, the optimism object of maximizingsidelobe attenuation and minimizing mainlobe ripple can be transformedto a goal beam pattern, and thus can be realized. Therefore, comparedwith Convex Optimization and Orthogonal Method which each can onlyrealize limited optimism objects, a wide range of use can be provided.

Meanwhile, since a certain kind of numeric method is used to calculatethe difference value, compared with metaheuristic methods in which alarge number of random attempts are based, this beamforming method andapparatus provide a much faster computing speed, and thus are practicalfor actual implementation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects of the present invention will become moreapparent from the following detailed description when taken inconjunction with the accompanying drawings in which:

FIG. 1 is a flowchart illustrating a beamforming method according to anembodiment of the present invention;

FIG. 2 is a detailed flowchart illustrating steps of data calculation ofFIG. 1;

FIG. 3 is a flowchart illustrating a beamforming method according toanother embodiment of the present invention;

FIG. 4 is a detailed flowchart illustrating steps of data calculation ofFIG. 3;

FIG. 5 is a flowchart illustrating a beamforming method according tostill another embodiment of the present invention;

FIG. 6 is a detailed flowchart illustrating steps of data calculation ofFIG. 5;

FIG. 7 is a flowchart illustrating a beamforming method according tostill another embodiment of the present invention;

FIG. 8 is a detailed flowchart illustrating steps of data calculation ofFIG. 7;

FIG. 9 is a schematic view illustrating a beamforming apparatusaccording to an embodiment of the present invention;

FIG. 10 is a schematic view illustrating a beamforming apparatusaccording to another embodiment of the present invention;

FIG. 11 is a schematic view illustrating a beamforming apparatusaccording to still another embodiment of the present invention; and

FIG. 12 is a schematic view illustrating a beamforming apparatusaccording to still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, embodiments will be describedwith reference to the accompanying drawings. However, the presentinvention may be embodied in various different forms, and should not beconstrued as being limited only to the illustrated embodiments. Rather,these embodiments are provided as examples, simply by way ofillustrating the concept of the present invention to those skilled inthe art. Accordingly, processes, elements, and techniques that should beapparent to those of ordinary skill in the art are not described herein.

FIG. 1 is a flowchart illustrating a beamforming method according to anembodiment of the present invention, and FIG. 2 is a detailed flowchartillustrating steps of data calculation of FIG. 1.

Referring to FIG. 1, a beamforming method according to an embodiment ofthe present invention will be described hereinafter.

At step S100, an optimism object input by a user is received. If it isdetermined that there is no given goal beam pattern included in theoptimism object, a goal beam pattern can be further established based onthe optimism object.

For example, for the optimism object of beam pattern matching, a goalbeam pattern will be included in the optimism object directly. And forthe optimism object of maximizing sidelobe attenuation and minimizingmainlobe ripple, there will be no goal beam pattern. In such a case, astep of establishing a goal beam pattern based on the optimism objectwill be further implemented. The detailed description of this step willbe omitted since it is well known for those skilled in the art.

In an embodiment, the goal beam pattern can be indicated as S(θ),wherein θ indicates direction angle.

At step S105, the data of all array elements are initialized, and then acurrent beam pattern which can be indicated as G(θ) is calculated basedon the initialized data. For example, amplitude w of each array elementis initialized as 1 which is the largest amplitude while 0 is thesmallest one, and phase φ of each array element is initialized as 0.

Then, at step S110, a threshold, for example, an iteration precisionwhich can be indicated as e, is preset based on the user's requirementof speed and accuracy for the optimization processes.

Hereinafter data calculation implemented at step S115 will be describedwith reference to FIG. 2, assuming there are n array elements.

At step S1150, a difference value, which can be indicated as f, betweenthe current beam pattern G(θ) and the goal beam pattern S(θ) iscalculated. In an embodiment, the difference value can be calculatedusing the equation of f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·dθ. Alternatively,equation of

${f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot d}\; \theta}}$

can be used. Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . .. , w_(n)) indicates the amplitudes of the n array elements, and ϕ=(ϕ₁,ϕ₂, . . . , ϕ_(n)) indicates phases of the n array elements. However,the present invention is not limited thereto. Instead, other calculationmethods based on integrals with respect to θ can be used provided thatit can indicate the difference between the current beam pattern G(θ) andthe goal beam pattern S(θ).

At step S1152, amplitude w_(i) and phase φ_(i) for each array elementare calculated to make the difference value f minimum in turn from thefirst array element to the nth array element, with the data of otherarray elements being held and determined data replacing previous data.That is, values of amplitudes and phases for other array elements areheld, and the determined values of amplitudes and phases replacing theprevious corresponding values.

For example, when the calculation is implemented for the first arrayelement, values of amplitudes and phases for the second to the nth arrayelements are held. And if this is the first time to implement the step,values of amplitudes and phases for the second to the nth array elementswill be 1 and 0 respectively. If this is the second or third time toimplement the step, values of amplitudes and phases for the second tothe nth array elements will be w₂-w_(n) and φ₂-φ_(n) which aredetermined in the last implementation of the step respectively.

As another example, when the calculation is implemented for the secondarray element, values of amplitudes and phases for the first and thethird to the nth array elements are held. And if this is the first timeto implement the step, values of amplitude and phase for the first arrayelement will be determined w₁ and φ₁ respectively, while values ofamplitudes and phases for the third to the nth array elements will be 1and 0 respectively. If this is the second or third time to implement thestep, values of amplitude and phase for the first array element will bew₁ and φ₁ determined in this implementation of the step, while values ofamplitudes and phases for the third to the nth array elements will bew₃-w_(n) and φ₃-φ_(n) which are determined in the last implementation ofthe step respectively.

As still another example, when the calculation is implemented for thenth array element, values of amplitudes and phases for the first to the(n−1)th array elements are held, and values of amplitudes and phases forthe first to the (n−1)th array element will be w₁-w_(n-1) and φ₁-φ_(n-1)determined in this implementation of the step respectively.

Any of the existing numerical methods, such as Conjugate GradientMethod, Gradient Descent Method, Newton's Method etc., can be used tocalculate the amplitude and the phase for each array element, anddetailed description thereof will be omitted since it is well known forthose skilled in the art.

At step S1154, a difference between the current difference value f andthe previous difference value f is calculated. Here, the currentdifference value f means the difference value f after thisimplementation of step S1152, while the previous difference value fmeans the difference value f before this implementation of step S1152,for example the value determined at step S1150 or the value determinedafter the last implementation of step S1152.

At step S1156, it is judged if the calculated difference is less thanthe iteration precision ε. If so, step S120 which will be describedlater will be implemented. Otherwise, step S1152 will be implementedagain for all of the n array elements.

It will be understood that steps S1154 and S1156 as well as S110 may beomitted in some cases to simplify the processing and provide a fastercomputing speed.

Referring back to FIG. 1, at step S120, the data of the current w₁-w_(n)and φ₁-φ_(n) are used to generate a beamforming vector. For example, theamplitude of each array element will be w₁-w_(n) respectively, and thephase of each array element will be φ₁-φ_(n) respectively.

Finally, at step S125, the signals to be transmitted through an antennaarray are generated using the beamforming vector.

With this beamforming method, since a goal beam pattern is determined atfirst, it can realize the optimism object of beam pattern matching ifthe goal beam pattern can be reached. Even if the goal beam patterncannot be reached and can only be approached, since iteration methodsare used in an embodiment, rather than direct computation like inOrthogonal Method, this beamforming method can also provide a goodresult. Thus compared with Orthogonal Method, it has a wide range ofuse.

Further, in another embodiment, the optimism object of maximizingsidelobe attenuation and minimizing mainlobe ripple can be transformedto a goal beam pattern, and thus can be realized. Therefore, comparedwith Convex Optimization and Orthogonal Method which each can onlyrealize limited optimism objects, a wide range of use can be provided.

Meanwhile, since a certain kind of numeric method is used to calculatethe difference value, compared with metaheuristic methods in which alarge number of random attempts are based, this beamforming methodprovides a much faster computing speed, and thus is practical for actualimplementation.

FIG. 3 is a flowchart illustrating a beamforming method according toanother embodiment of the present invention, and FIG. 4 is a detailedflowchart illustrating steps of data calculation of FIG. 3.

Referring to FIG. 3, a beamforming method according to this embodimentwill be described hereinafter, wherein steps S300 to S310 are similar tosteps S100 to S110 of FIG. 1 and detailed description thereof will beomitted.

At step S311, a main weight function which can be indicated as P₁(θ) isinitialized. For example, P₁(θ) can be initialized as

$\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}$

That is,

${P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}}$

However, the present invention is not limited thereto. Instead, otherequations could be used provided that it can enlarge a difference valuebetween the current beam pattern G(θ) and the goal beam pattern S(θ)which will be described in the next step.

Hereinafter data calculation implemented at step S315 will be describedwith reference to FIG. 4, assuming there are n array elements.

At step S3150, a difference value f between the current beam patternG(θ) and the goal beam pattern S(θ) is calculated. In this embodiment ofthe present invention, the difference value can be calculated using theequation of f(w,ϕ))=∫₀ ^(π)(G(θ)−S(θ))²·P₁(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot {P_{1}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to B as well as P₁(θ) could be usedprovided that it can indicate the difference value between the currentbeam pattern G(θ) and the goal beam pattern S(θ).

At step S3152, similar to step S1152, amplitude w_(i) and phase φ_(i)for each array element are calculated to make the difference value fminimum in turn from the first array element to the nth array element,with amplitudes and phases for other array elements being held meanwhilethe determined values of amplitudes and phases replacing the previouscorresponding values.

Compared with step S1152, a further step is included: each time afterdata which makes the difference value minimum for an array element isdetermined, updating the main weight function based on the determineddata. And the updated main weight function will be used in thecalculation for the next array element.

In detail, after values of amplitude w_(i) and phase φ_(i) for the itharray element are calculated, P₁(θ) will be updated, i.e., recalculated,using the equation in step S311 based on the determined w_(i) and φ_(i)And the updated P₁(θ) will be used in the calculation for the (i+l)tharray element. For example, after values of amplitude w₁ and phase φ₁for the first array element are calculated, P₁(θ) will be recalculatedusing the equation in step S311 based on the determined w₁ and φ₁. Theupdated P₁(θ) will be used in the calculation for the second arrayelement.

At step S3154, a difference between the current difference value f andthe previous difference value f is calculated. Here, the currentdifference value f means the difference value f after thisimplementation of step S3152, while the previous difference value fmeans the difference value f before this implementation of step S3152,for example the value determined at step S3150 or the value determinedafter the last implementation of step S3152.

At step S3156, it is judged if the calculated difference is less thanthe iteration precision E. If so, step S320 which will be describedlater will be implemented. Otherwise, step S3152 will be implementedagain for all of the n array elements.

It will be understood that steps S3154 and S3156 as well as S310 may beomitted in some cases to simplify the processing and provide a fastercomputing speed.

Referring back to FIG. 3, at step S320, the data of the current w₁-w_(n)and φ₁-φ_(n) are used to generate a beamforming vector. For example, theamplitude of each array element will be w₁-w_(n) respectively, and thephase of each array element will be φ₁-φ_(n) respectively.

Finally, at step S325, the signals to be transmitted through an antennaarray are generated using the beamforming vector.

With the beamforming method according to this embodiment, since the mainweight function is used, the difference between the current beam patternand the goal beam pattern at those direction angels where G(θ) and S(θ)are considerably small (e.g the deep nulls of the sidelobe) is enlarged,thus the computing speed is further increased greatly.

FIG. 5 is a flowchart illustrating a beamforming method according tostill another embodiment of the present invention, and FIG. 6 is adetailed flowchart illustrating steps of data calculation of FIG. 5.

Referring to FIG. 5, a beamforming method according to this embodimentwill be described hereinafter, wherein steps S500 to S510 are similar tosteps S100 to S110 of FIG. 1 and detailed description thereof will beomitted.

At step S512, a secondary weight function which can be indicated asP₂(θ) is initialized, for example as 1. That is, P₂(θ)=1.

At step S513, a condition which can be indicated as OP is preset basedon the optimism object.

Hereinafter data calculation implemented at step S515 will be describedwith reference to FIG. 6, assuming there are n array elements.

At step S5150, a difference value f between the current beam patternG(θ) and the goal beam pattern S(θ) is calculated. In this embodiment ofthe present invention, the difference value can be calculated using theequation of f(w,ϕ))=∫₀ ^(π)(G(θ)−S(θ))²·P₂(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot {P_{2}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to θ as well as P₂(θ) could be usedprovided that it can indicate the difference between the current beampattern G(θ) and the goal beam pattern S(θ).

The following steps S5152 to S5156 are similar to step S1152 to S1156 ofFIG. 2, detailed description thereof will be omitted in order to avoidredundancy.

At step S516, it is further judged if the current beam pattern meets thecondition OP. If so, step S520 will be implemented. Otherwise, step S517will be implemented.

At step S517, the secondary weight function P₂(θ) is adjusted by addinga positive number to the secondary weight for the angles in which thecorresponding current beam pattern does not meet the condition OP. Thatis, the current P₂(θ_(not satisfied)) will be increased U. Here,θ_(not satisfied) indicates the angles in which the correspondingcurrent beam pattern does not meet the condition OP, and U is a positivenumber. After that, the method will go back to step S5152, that is, anew turn of data calculation will be implemented.

At step S520, the data of the current w₁-w_(n) and φ₁-φ_(n) are used togenerate a beamforming vector. For example, the amplitude of each arrayelement will be w₁-w_(n) respectively, and the phase of each arrayelement will be φ₁-φ_(n) respectively.

Finally, at step S525, the signals to be transmitted through an antennaarray are generated using the beamforming vector.

With the beamforming method according to this embodiment of the presentinvention, the secondary weight function if further used and a furthercomparison is made to judge if the obtained beam pattern meets thecondition. And if the condition is not met, the secondary weightfunction will be added a positive number and a further turn of datacalculation will be implemented. Accordingly, the finally obtained beampattern will be closer to the goal beam pattern compared with theembodiments in which no secondary weight function is used and thus thismethod is especially applicable to realize the optimism object ofmaximizing sidelobe attenuation and minimizing mainlobe ripple.

FIG. 7 is a flowchart illustrating a beamforming method according tostill another embodiment of the present invention, and FIG. 8 is adetailed flowchart illustrating steps of data calculation of FIG. 7.

Referring to FIG. 7, a beamforming method according to this embodimentwill be described hereinafter, wherein steps S700 to S710 are similar tosteps S100 to S110 of FIG. 1 and detailed description thereof will beomitted.

At step S711, a main weight function which can be indicated as P₁(θ) isinitialized. For example, P₁(θ) can be initialized as

$\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}$

That is,

${P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}}$

However, the present invention is not limited thereto. Instead, otherequations could be used provided that it can enlarge a difference valuebetween the current beam pattern G(θ) and the goal beam pattern S(θ)which will be described in the following step S715.

At step S712, a secondary weight function which can be indicated asP₂(θ) is further initialized, for example as 1. That is, P₂(θ)=1.

At step S713, a condition which can be indicated as OP is preset basedon the optimism object.

Hereinafter data calculation implemented at step S715 will be describedwith reference to FIG. 8, assuming there are n array elements.

At step S7150, a difference value f between the current beam patternG(θ) and the goal beam pattern S(θ) is calculated. In this embodiment,the difference value can be calculated using the equation of f(w,ϕ)=∫₀^(π)(G(θ)−S(θ))²·P₁(θ) P₂(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to θ as well as P₁ (θ) and P₂(θ)provided that it can indicate the difference between the current beampattern G(θ) and the goal beam pattern S(θ).

The following steps S7152 to S7156 are similar to steps S3152 to S3156of FIG. 4, and the following steps S716 to S725 are similar to stepsS516 to S525 of FIG. 5, thus detailed description thereof will beomitted in order to avoid redundancy.

With the beamforming method according to this embodiment, both of themain weight function and the secondary weight function are used, thusthis method not only provides a fast computing speed, but also isespecially applicable to realize the optimism object of maximizingsidelobe attenuation and minimizing mainlobe ripple.

A beamforming apparatus according to an embodiment of the presentinvention will be described with reference to FIG. 9.

As shown in FIG. 9, a beamforming apparatus 10 according to anembodiment of the present invention includes an input receiving unit100, a data initializing unit 105, a threshold presetting unit 110, adata calculation unit 115, a beamforming vector generating unit 120 anda signal generating unit 125.

The input receiving unit 100 receives an optimism object input by auser. If it is determined that there is no given goal beam patternincluded in the optimism object, a goal beam pattern can be furtherestablished in the input receiving unit 100 based on the optimismobject.

In an embodiment, the goal beam pattern can be indicated as S(θ),wherein θ indicates direction angle.

The data initializing unit 105 initializes data of all array elementsand then calculates a current beam pattern which can be indicated asG(θ) based on the initialized data. For example, amplitude w of eacharray element is initialized as 1 which is the largest amplitude while 0is the smallest one, phase φ of each array element is initialized as 0.

The threshold presetting unit 110 presets a threshold, for example, aniteration precision which can be indicated as e, based on the user'srequirement of speed and accuracy for the optimization processesreceived also by the input receiving unit 100.

The data calculation unit 115 firstly calculates a difference value fbetween the current beam pattern G(θ) output from the data initializingunit 105 and the goal beam pattern S(θ) output from the input receivingunit 100. In an embodiment, the difference value can be calculated usingthe equation of f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·dθ. Alternatively, equationof

${f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot d}\; \theta}}$

can be used. Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . .. , w_(n)) indicates the amplitudes of the n array elements, and ϕ=(ϕ₁,ϕ₂, . . . , ϕ_(n)) indicates phases of the n array elements. However,the present invention is not limited thereto. Instead, other calculationmethods based on integrals with respect to θ can be used provided thatit can indicate the difference between the current beam pattern G(θ) andthe goal beam pattern S(θ).

Then, the data calculation unit 115 implements data calculation for allof the array elements. In detail, amplitude w_(i) and phase φ_(i) foreach array element are calculated to make the difference value f minimumin turn from the first array element to the nth array element, with thedata of other array elements being held and determined data replacingprevious data. That is, values of amplitudes and phases for other arrayelements are held, and the determined values of amplitudes and phasesreplacing the previous corresponding values.

Any of the existing numerical methods, such as Conjugate GradientMethod, Gradient Descent Method, Newton's Method etc., can be used tocalculate the amplitude and the phase for each array element, anddetailed description thereof will be omitted since it is well known forthose skilled in the art.

In the data calculation unit 115, a difference between the currentdifference value f and the previous difference value f is thencalculated, and it is further judged if the calculated difference isless than the iteration precision e which is output from the thresholdpresetting unit 110. If so, the data of the current w₁-w_(n) andφ₁-φ_(n) will be sent to the beamforming vector generating unit 120.Otherwise, amplitude w_(i) and phase φ_(i) for each array element willbe implemented again for all of the n array elements.

It will be understood that the steps of calculating the differencebetween the current difference value f and the previous difference valuef and further judging if the calculated difference is less than theiteration precision e as well as the threshold presetting unit 110 maybe omitted in some cases to simplify the processing and provide a fastercomputing speed.

The beamforming vector generating unit 120 generates a beamformingvector using the data of the current w₁-w_(n) and φ₁-φ_(n) sent from thedata calculation unit 115. For example, the amplitude of each arrayelement will be w₁-w_(n) respectively, and the phase of each arrayelement will be φ₁-φ_(n) respectively.

The signal generating unit 125 generates the signals to be transmittedthrough an antenna array using the beamforming vector sent from thebeamforming vector generating unit 120.

Similar to the beamforming method as shown in FIGS. 1 and 2, thebeamforming apparatus according to this has a wide range of use and afast computing speed.

FIG. 10 shows a schematic view illustrating a beamforming apparatusaccording to another embodiment of the present invention. As shown inFIG. 10, a beamforming apparatus 30 according to this embodimentincludes an input receiving unit 300, a data initializing unit 305, athreshold presetting unit 310, a main weight function initializing unit311, a data calculation unit 315, a beamforming vector generating unit320 and a signal generating unit 325.

The input receiving unit 300, the data initializing unit 305 and thethreshold presetting unit 310 are similar to the input receiving unit100, the data initializing unit 105 and the threshold presetting unit110 of FIG. 9, and detailed description thereof will be omitted.

The main weight function initializing unit 311 initializes a main weightfunction which can be indicated as P₁(θ), for example, as

$\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}$

That is,

${P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}}$

However, the present invention is not limited thereto. Instead, otherequations could be used provided that it can enlarge a difference valuebetween the current beam pattern G(θ) and the goal beam pattern S(θ).

The data calculation unit 315 firstly calculates a difference value fbetween the current beam pattern G(θ) sent from the data initializingunit 305 and the goal beam pattern S(θ) sent from the input receivingunit 300. In an embodiment, the difference value can be calculated basedon P₁(θ) output from the main weight function initializing unit 311, forexample using the equation of f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₁(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot {P_{1}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to B as well as P₁(θ) could be usedprovided that it can indicate the difference value between the currentbeam pattern G(θ) and the goal beam pattern S(θ).

Secondly, the data calculation unit 315 implements data calculation forall of the array elements. In detail, amplitude w_(i) and phase φ_(i)for each array element are calculated to make the difference value fminimum in turn from the first array element to the nth array element,with amplitudes and phases for other array elements being held meanwhilethe determined values of amplitudes and phases replacing the previouscorresponding values.

Furthermore, each time after data which makes the difference valueminimum for an array element is determined, the main weight function isupdated in the data calculation unit 315 based on the determined data,and the updated main weight function will be used in the calculation forthe next array element.

Also, in the data calculation unit 315, a difference between the currentdifference value f and the previous difference value f is thencalculated, and it is further judged if the calculated difference isless than the iteration precision ε which is output from the thresholdpresetting unit 310. If so, the data of the current w₁-w_(n) andφ₁-φ_(n) will be sent to the beamforming vector generating unit 320.Otherwise, amplitude w_(i) and phase φ_(i) for each array element willbe implemented again for all of the n array elements.

It will be understood that the steps of calculating the differencebetween the current difference value f and the previous difference valuef and further judging if the calculated difference is less than theiteration precision ε as well as the threshold presetting unit 310 maybe omitted in some cases to simplify the processing and provide a fastercomputing speed.

The beamforming vector generating unit 320 generates a beamformingvector using the data of the current w₁-w_(n) and φ₁-φ_(n) sent from thedata calculation unit 315. For example, the amplitude of each arrayelement will be w₁-w_(n) respectively, and the phase of each arrayelement will be φ₁-φ_(n) respectively.

The signal generating unit 325 generates the signals to be transmittedthrough an antenna array using the beamforming vector sent from thebeamforming vector generating unit 320.

Similar to the beamforming method as shown in FIGS. 3 and 4, thebeamforming apparatus according to this has a greatly increasedcomputing speed compared with the beamforming apparatus as shown in FIG.9.

FIG. 11 shows a schematic view illustrating a beamforming apparatusaccording to still another embodiment of the present invention. As shownin FIG. 11, a beamforming apparatus 50 according to this embodimentincludes an input receiving unit 500, a data initializing unit 505, athreshold presetting unit 510, a secondary weight function initializingunit 512, a condition presetting unit 513, a data calculation unit 515,a condition judging unit 516, a secondary weight function adjusting unit517, a beamforming vector generating unit 520 and a signal generatingunit 525.

The input receiving unit 500, the data initializing unit 505 and thethreshold presetting unit 510 are similar to the input receiving unit100, the data initializing unit 105 and the threshold presetting unit110 of FIG. 9, and detailed description thereof will be omitted.

The secondary weight function initializing unit 512 initializes asecondary weight function which can be indicated as P₂(θ), for example,as 1. That is, P₂(θ)=1.

The condition presetting unit 513 presets a condition which can beindicated as OP based on the optimism object output from the inputreceiving unit 500.

The data calculation unit 515 firstly calculates a difference value fbetween the current beam pattern G(θ) output from the data initializingunit 505 and the goal beam pattern S(θ) output from the input receivingunit 500. In an embodiment, the difference value can be calculated usingthe equation of f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₂(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)}\  \cdot {P_{2}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to θ as well as P₂(θ) could be usedprovided that it can indicate the difference between the current beampattern G(θ) and the goal beam pattern S(θ).

Next, the data calculation unit 515 implements data calculation which issimilar to the data calculation implemented in the data calculation unit115 of FIG. 9, detailed description thereof will be omitted in order toavoid redundancy.

The condition judging unit 516 judges if the current beam pattern meetsthe condition OP output from the condition presetting unit 513. If so,the condition judging unit 516 will send the judging result of thecondition being met to the data calculation unit 515 which will thensend the current w₁-w_(n) and φ₁-φ_(n) to the beamforming vectorgenerating unit 520. Otherwise, the judging result of the conditionbeing not met will be sent to the secondary weight function adjustingunit 517.

The secondary weight function adjusting unit 517 updates the secondaryweight function P₂(θ) by adding a positive number to the secondaryweight function P₂(θ) for the angles in which the corresponding currentbeam pattern does not meet the condition OP after receiving the judgingresult of the condition being not met. That is, the currentP₂(θ_(not satisfied)) will be increased U. Here, S_(not satisfied)indicates the angles in which the corresponding current beam patterndoes not meet the condition OP, and U is a positive number. After that,the secondary weight function adjusting unit 517 will output theadjusted secondary weight function to the data calculation unit 515 sothat it can be used in a new turn of data calculation.

The beamforming vector generating unit 520 generates a beamformingvector using the data of the current w₁-w_(n) and φ₁-φ_(n) sent from thedata calculation unit 515. For example, the amplitude of each arrayelement will be w₁-w_(n) respectively, and the phase of each arrayelement will be φ₁-φ_(n) respectively.

The signal generating unit 525 generates the signals to be transmittedthrough an antenna array using the beamforming vector sent from thebeamforming vector generating unit 520.

Similar to the beamforming method as shown in FIGS. 5 and 6, thebeamforming apparatus according to this embodiment is especiallyapplicable to realize the optimism object of maximizing sidelobeattenuation and minimizing mainlobe ripple.

FIG. 12 shows a schematic view illustrating a beamforming apparatusaccording to still another embodiment of the present invention. As shownin FIG. 12, a beamforming apparatus 70 according to this embodimentincludes an input receiving unit 700, a data initializing unit 705, athreshold presetting unit 710, a main weight function initializing unit711, a secondary weight function initializing unit 712, a conditionpresetting unit 713, a data calculation unit 715, a condition judgingunit 716, a secondary weight function adjusting unit 717, a beamformingvector generating unit 720 and a signal generating unit 725.

The input receiving unit 700, the data initializing unit 705 and thethreshold presetting unit 710 are similar to the input receiving unit100, the data initializing unit 105 and the threshold presetting unit110 of FIG. 9, and detailed description thereof will be omitted.

The main weight function initializing unit 711 initializes a main weightfunction which can be indicated as P₁(θ), for example, as

$\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}$

That is,

${P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = {\frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}.}}$

The secondary weight function initializing unit 712 initializes asecondary weight function which can be indicated as P₂(θ), for example,as 1. That is, P₂ (θ)=1.

The condition presetting unit 713 presets a condition which can beindicated as OP based on the optimism object output from the inputreceiving unit 700.

The data calculation unit 715 firstly calculates a difference value fbetween the current beam pattern G(θ) output from the data initializingunit 705 and the goal beam pattern S(θ) output from the input receivingunit 700. In an embodiment, the difference value can be calculated usingthe equation of f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₁(θ)·P₂(θ)·dθ or

${f( {w,\varphi} )} = {\frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}.}$

Here, f(w,ϕ) indicates the difference value, w=(w₁, w₂, . . . , w_(n))indicates the amplitudes of the n array elements, and ϕ=(ϕ₁, ϕ₂, . . . ,ϕ_(n)) indicates phases of the n array elements. However, the presentinvention is not limited thereto. Instead, other calculation methodsbased on integrals with respect to θ as well as P₁(θ) and P₂(θ) providedthat it can indicate the difference between the current beam patternG(θ) and the goal beam pattern S(θ).

Next, the data calculation unit 715 implements data calculation which issimilar to the data calculation in the data calculation unit 315 of FIG.10. Furthermore, the condition judging unit 716, the secondary weightfunction adjusting unit 717, the beamforming vector generating unit 720and the signal generating unit 725 are similar to the condition judgingunit 516, the secondary weight function adjusting unit 517, thebeamforming vector generating unit 520 and the signal generating unit525 of FIG. 11, detailed description thereof will be omitted in order toavoid redundancy.

Similar to the beamforming method as shown in FIGS. 7 and 8, thebeamforming apparatus according to this embodiment not only provides afast computing speed, but also is especially applicable to realize theoptimism object of maximizing sidelobe attenuation and minimizingmainlobe ripple.

While the present disclosure has been described with reference toexemplary embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the present invention. Therefore, the aboveembodiments are provided for illustrative purposes only, and should notin any sense be interpreted as limiting the scope of the presentdisclosure.

1. A beamforming method, comprising the steps of: initializing data ofarray elements of an antenna array and calculating a current beampattern based on the initialized data; calculating a difference valuebetween the current beam pattern and a goal beam pattern, anddetermining data which makes the difference value minimum respectivelyfor each array element using a numerical method in turn from the firstarray element to the last array element, with the data of other arrayelements being held and determined data replacing previous data; andgenerating a beamforming vector using the determined data and generatingsignals to be transmitted using the beamforming vector.
 2. Thebeamforming method according to claim 1, further comprising repeatingthe step of determining data until a difference between the currentdifference value and the previous difference value is less than a presetthreshold.
 3. The beamforming method according to claim 1, wherein thefollowing equation is used to calculate the difference value between thecurrent beam pattern and the goal beam pattern: f(w,ϕ)=∫₀^(π)(G(θ)−S(θ))²·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements, ϕ indicates phases of the array elements, θindicates direction angle, G(θ) indicates the current beam pattern, andS(θ) indicates the goal beam pattern.
 4. The beamforming methodaccording to claim 1, further comprising: initializing a main weightfunction; wherein the step of calculating the difference value betweenthe current beam pattern and the goal beam pattern includes calculatingthe difference value based on the main weight function; and the methodfurther comprising: each time after data which makes the differencevalue minimum for an array element is determined, updating the mainweight function based on the determined data.
 5. The beamforming methodaccording to claim 4, wherein the main weight function is initialed andupdated as${{P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = \frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}}},$wherein P₁(θ) indicates the main weight function, θ indicates directionangle, G(θ) indicates the current beam pattern, and S(θ) indicates thegoal beam pattern; and wherein the following equation is used tocalculate the difference value between the current beam pattern and thegoal beam pattern: f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₁(θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements and ϕ indicates phases of the array elements.
 6. Thebeamforming method according to claim 1, further comprising:initializing a secondary weight function; wherein the step ofcalculating the difference value between the current beam pattern andthe goal beam pattern includes calculating the difference value based onthe secondary weight function; and the method further comprising:adjusting the secondary weight function by adding a positive number forthe angles in which the corresponding current beam pattern does not meeta preset condition before forming the beamforming vector, andimplementing the step of determining data again based on the updatedsecondary weight function.
 7. The beamforming method according to claim6, wherein the secondary weight function is initialized as P₂ (θ)=1,wherein P₂(θ) indicates the secondary weight function, wherein thefollowing equation is used to calculate the difference value between thecurrent beam pattern and the goal beam pattern: f(w,ϕ)=∫₀^(π)(G(θ)−S(θ))²·P₂(θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements, ϕ indicates phases of the array elements, θindicates direction angle, G(θ) indicates the current beam pattern andS(θ) indicates the goal beam pattern.
 8. The beamforming methodaccording to claim 1, further comprising: initializing a main weightfunction and a secondary weight function; wherein the step ofcalculating the difference value between the current beam pattern andthe goal beam pattern includes calculating the difference value based onthe main weight function and the secondary weight function; and themethod further comprising: each time after data which makes thedifference value minimum for an array element is determined, updatingthe main weight function based on the determined data; updating thesecondary weight function by adding a positive number for the angles inwhich the corresponding current beam pattern does not meet a presetcondition before forming the beamforming vector, and implementing thestep of determining data again based on the updated secondary weightfunction.
 9. The beamforming method according to claim 8, wherein themain weight function is initialed and updated as${{P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = \frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}}},$wherein P₁(θ) indicates the main weight function, θ indicates directionangle, G(θ) indicates the current beam pattern, and S(θ) indicates thegoal beam pattern; wherein the secondary weight function is initializedas P₂ (θ)=1, wherein P₂(θ) indicates the secondary weight function; andwherein the following equation is used to calculate the difference valuebetween the current beam pattern and the goal beam pattern: f(w,ϕ)=∫₀^(π)(G(θ)−S(θ))²·P₁(θ)·P₂(θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements and ϕ indicates phases of the array elements.
 10. Thebeamforming method according to claim 1, further comprising establishinga goal beam pattern based on an optimism object if the optimism objectdoes not include the goal beam pattern.
 11. A beamforming apparatus,comprising: an input receiving unit configured to receive a goal beampattern; a data initializing unit configured to initialize data of arrayelements of an antenna array pattern and calculate a current beampattern based on the initialized data; a data calculation unitconfigured to calculate a difference value between the current beampattern output from the data initializing unit and the goal beam patternoutput from the input receiving unit, and determine data which makes thedifference value minimum respectively for each array element using anumerical method in turn from the first array element to the last arrayelement, with the data of other array elements being held and determineddata replacing previous data; a beamforming vector generating unitconfigured to generate a beamforming vector using the determined datasent from the data calculation unit; and a signal generating unitconfigured to generate signals to be transmitted using the beamformingvector sent from the beamforming vector generating unit.
 12. Thebeamforming apparatus according to claim 11, further comprising athreshold presetting unit configured to preset a threshold, wherein thedata calculation unit is further configured to repeat the step ofdetermining data until a difference between the current difference valueand the previous difference value is less than the preset thresholdoutput from the threshold presetting unit.
 13. The beamforming apparatusaccording to claim 11, wherein the following equation is used tocalculate the difference value between the current beam pattern and thegoal beam pattern: f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitude, windicates amplitudes of the array elements, ϕ indicates phases of thearray elements, G(θ) indicates the current beam pattern, and S(θ)indicates the goal beam pattern.
 14. The beamforming apparatus accordingto claim 11, further comprising a main weight function initializing unitconfigured to initialize a main weight function, wherein the datacalculation unit calculates the difference value between the currentbeam pattern and the goal beam pattern based on the main weight functionoutput from the main weight function initializing unit; and wherein thedata calculation unit is further configured to: each time after datawhich makes the difference value minimum for an array element isdetermined, update the main weight function based on the determineddata.
 15. The beamforming apparatus according to claim 14, wherein themain weight function is initialed and updated as${{P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = \frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}}},$wherein P₁(θ) indicates the main weight function, θ indicates directionangle, G(θ) indicates the current beam pattern, and S(θ) indicates thegoal beam pattern; and wherein the following equation is used tocalculate the difference value between the current beam pattern and thegoal beam pattern: f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₁(θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{1}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements and ϕ indicates phases of the array elements.
 16. Thebeamforming apparatus according to claim 11, further comprising asecondary weight function initializing unit configured to initialize asecondary weight function; wherein the data calculation unit calculatesthe difference value between the current beam pattern and the goal beampattern based on the secondary weight function output from the secondaryweight function initializing unit; and the beamforming apparatus furthercomprising: a condition presetting unit configured to preset acondition; a condition judging unit configured to judge if the currentbeam pattern meets the condition output from the condition presettingunit, and send the judging result of the condition being met to the datacalculation unit if the condition is met, and send the judging result ofthe condition being not met to the secondary weight function adjustingunit if the condition is not met; a secondary weight function adjustingunit configured to adjust the secondary weight function by adding apositive number for the angles in which the corresponding current beampattern does not meet a preset condition, and output the adjustedsecondary weight function to the data calculation unit, wherein the datacalculation unit is further configured to implement the step ofdetermining data again based on the updated secondary weight functionoutput from the secondary weight function adjusting unit, and send thedetermined data to the beamforming vector generating unit afterreceiving the judging result of the condition being met.
 17. Thebeamforming apparatus according to claim 16, wherein the secondaryweight function is initialized as P₂(θ)=1, wherein P₂(θ) indicates thesecondary weight function, wherein the following equation is used tocalculate the difference value between the current beam pattern and thegoal beam pattern: f(w,ϕ)=∫₀ ^(π)(G(θ)−S(θ))²·P₂θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements, ϕ indicates phases of the array elements, θindicates direction angle, G(θ) indicates the current beam pattern andS(θ) indicates the goal beam pattern.
 18. The beamforming apparatusaccording to claim 11, further comprising: a main weight functioninitializing unit configured to initialize a main weight function; asecondary weight function initializing unit configured to initialize asecondary weight function; wherein the data calculating unit calculatesthe difference value between the current beam pattern and the goal beampattern based on the main weight function output from the main weightfunction initializing unit and the secondary weight function output fromthe secondary weight function initializing unit; and the beamformingapparatus further comprising: a condition presetting unit configured topreset a condition; a condition judging unit configured to judge if thecurrent beam pattern meets the condition output from the conditionpresetting unit, and send the judging result of the condition being metto the data calculation unit if the condition is met, and send thejudging result of the condition being not met to the secondary weightfunction adjusting unit if the condition is not met; a secondary weightfunction adjusting unit configured to adjust the secondary weightfunction by adding a positive number for the angles in which thecorresponding current beam pattern does not meet a preset condition, andoutput the adjusted secondary weight function to the data calculationunit, wherein the numerical calculation unit is further configured to:each time after data which makes the difference value minimum for anarray element is determined, update the main weight function based onthe determined data; implement the step of determining data again basedon the updated secondary weight function output from the secondaryweight function adjusting unit; and send the determined data to thebeamforming vector generating unit after receiving the judging result ofthe condition being met.
 19. The beamforming apparatus according toclaim 18, wherein the main weight function is initialed and updated as${{P_{1}(\theta)} = {{\frac{1}{G(\theta)}\mspace{14mu} {or}\mspace{14mu} {P_{1}(\theta)}} = \frac{{{G(\theta)} - {S(\theta)}}}{G(\theta)}}},$wherein P₁(θ) indicates the main weight function, θ indicates directionangle, G(θ) indicates the current beam pattern, and S(θ) indicates thegoal beam pattern; wherein the secondary weight function is initializedas P₂(θ)=1, wherein P₂(θ) indicates the secondary weight function; andwherein the following equation is used to calculate the difference valuebetween the current beam pattern and the goal beam pattern: f(w,ϕ)=∫₀^(π)(G(θ)−S(θ))²·P₁(θ)·P₂(θ)·dθ or${{f( {w,\varphi} )} = \frac{\sqrt{\int_{0}^{\pi}{{{G(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; {\theta \cdot {\int_{0}^{\pi}{{{S(\theta)}^{2} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}}}}}{\int_{0}^{\pi}{{{G(\theta)} \cdot {S(\theta)} \cdot {P_{1}(\theta)} \cdot {P_{2}(\theta)} \cdot d}\; \theta}}},$wherein f(w,ϕ) indicates the difference value, w indicates amplitudes ofthe array elements and ϕ indicates phases of the array elements.
 20. Thebeamforming apparatus according to claim 11, wherein the input receivingunit is further configured to establish a goal beam pattern based on anoptimism object if the optimism object does not include the goal beampattern.